Smectogenic asymmetric naphthalene derived chalcones: Self-assembling behaviour and DFT studies

•A series of new asymmetrical self-assembling naphthalene benzoate derived chalcones have been synthesized.•Existence of enantiotropic smectic-A (SmA) & tilted SmC mesophase was revealed.•VT-XRD analysis has been carried out to confirm the mesophase present.•DFT method provide the relationship between the computed structural and electronic variables with mesomorphism. A series of new naphthalene derived asymmetric benzoates incorporating chalcone unit NPCH-(2–16) have been synthesized and investigated for their self-assembling behaviour. The naphthalene end of molecules linked to decyloxy long chain whereas the other end possess systematically substituted chalcone unit connected through ester and imine linking mesogenic units. New molecules have been found to exhibit smectogenic behaviour investigated by POM (polarising optical microscopy) and DSC (differential scaling calorimetry) investigations. Early members (C1 and C7) showed enantiotropic smectic-A (SmA) behaviour, whereas molecules with C8 and C10 showed enantiotropic SmA along with monotropic smectic-C (SmC) also during cooling scans. All afterwards molecules (C12-C16) with longer alkyl chains tend to exhibit enantiotropic SmC mesophase. For one of the representative compounds, the presence of mesophase was confirmed by VT-XRD (variable temperature X-ray-crystallography) analysis. Additionally, the density functional theory (DFT) method has been applied to provide an in-depth analysis of the relationship between the computed structural (length, aspect ratio) and electronic (dipole moment, polarizability) variables and the mesomorphic behaviour of investigated compounds. [Display omitted]